Enve makes high end stuff across an array of components (forks, bars, posts, etc). I was recently shopping carbon forks to upgrade my cdale CAAD. Stood down when I discovered a crack in my frame but what I found was that Enve and Ritchey emerged as really as only options anymore in the aftermarket carbon fork space, with maybe 3T as an option as well but they are not as widely available. Even Easton seems to be moving away from forks since I found very little availability.

Enve seems to have more options by way of tapered steerer than Ritchey but are more expensive than Ritchey (you could go lighter and pricier if you go with Enve 1.0 over 2.0 by the way).

Does cannondale not offer replacement forks for their bikes? If you are dealing with an LBS that is a cannondale dealer, getting a fork from c,dale might be an option.